Index: src/opts/SkBlitMask_opts.h |
diff --git a/src/opts/SkBlitMask_opts.h b/src/opts/SkBlitMask_opts.h |
new file mode 100644 |
index 0000000000000000000000000000000000000000..9129560ef4de7d84ceda58786d2cdb304cda17a7 |
--- /dev/null |
+++ b/src/opts/SkBlitMask_opts.h |
@@ -0,0 +1,37 @@ |
+/* |
+ * Copyright 2015 Google Inc. |
+ * |
+ * Use of this source code is governed by a BSD-style license that can be |
+ * found in the LICENSE file. |
+ */ |
+ |
+#ifndef SkBlitMask_opts_DEFINED |
+#define SkBlitMask_opts_DEFINED |
+ |
+#include "Sk4px.h" |
+ |
+namespace SK_OPTS_NS { |
+ |
+static void blit_mask_d32_a8(SkPMColor* dst, size_t dstRB, |
+ const SkAlpha* mask, size_t maskRB, |
+ SkColor color, int w, int h) { |
+ auto s = Sk4px::DupPMColor(SkPreMultiplyColor(color)); |
+ |
+ auto fn = [&](const Sk4px& d, const Sk4px& aa) { |
+ // = (s + d(1-sa))aa + d(1-aa) |
+ // = s*aa + d(1-sa*aa) |
+ auto left = s.approxMulDiv255(aa), |
+ right = d.approxMulDiv255(left.alphas().inv()); |
+ return left + right; // This does not overflow (exhaustively checked). |
+ }; |
+ |
+ while (h --> 0) { |
+ Sk4px::MapDstAlpha(w, dst, mask, fn); |
+ dst += dstRB / sizeof(*dst); |
+ mask += maskRB / sizeof(*mask); |
+ } |
+} |
+ |
+} // SK_OPTS_NS |
+ |
+#endif//SkBlitMask_opts_DEFINED |